David Cameron today demanded a deadline be set for Syria to destroy its stock pile of chemical weapons, in an apparent breakthrough in the international stand-off.

With US Congress poised to vote on missile strikes against the Assad regime, the Syrian government dramatically accepted a Russian proposal to turn over control of its chemical weapons to the international community.

Britain, France and America planned to table a UN security council resolution as early as today, setting thresholds and timetables for the plan to come into effect - but Russia appears set to veto it.

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Caution: Prime Minister David Cameron warned that more detail was needed to see if Syria was 'serious' about handing over its stockpile of chemical weapons

The idea emerged yesterday in an
apparent gaffe by US Secretary of State John Kerry who announced that
Assad could avoid U.S. military action by turning over 'every single bit
of his chemical weapons to the international community in the next
week.'

Speaking in London he added: 'But he isn’t about to do it, and it can't be done, obviously.'

But within hours Syrian Foreign
Minister Walid al-Moualem and his Russian counterpart Sergei Lavrov both
expressed interest in the plan as did UN Secretary General Ban Ki-moon.

Smoke rises from buildings due to heavy artillery shelling in Barzeh, a district of Damascus, Syria, today

He spoke to President Obama about the idea during the G20 in Russia on Friday. The two men spoke on the phone today after ‘things moved faster than was anticipated’, Mr Cameron said.

He said the security council resolution would be drafted to give 'some clarity about thresholds, that there’s some proper timetable, some proper policies'

'And crucially that there has to be confidence to ensure it is done. Of course we should be sceptical. Of course we should not forget that a major war crime has been committed.

'I think we do need some deadlines. We do need some timetables. It is not about someone monitoring chemical weapons in Syria.

'It’s got to be about handing them over to the intervational community and destroying them.'

Laurent Fabius says France, a permanent member of the 15-nation U.N. body, will start the resolution process on today.

Fabius
said the proposal will be under Chapter 7 of the U.N. charter - which
would back up the resolution with a threat of force if not applied - and
will 'condemn' a chemical weapons attack in Syria on August 21.

Foreign Secretary William Hague said: 'We have to make sure that this is not just a distraction tactic'

Foreign Secretary William Hague also urged caution, saying: 'How do you tell the difference between breakthroughs and delay tactics? That's exactly what we have to think about here.

'We have to make sure that this is not just a distraction tactic.'

French officials said their draft resolution was designed to make sure the Russian proposal would have teeth, by allowing military action if Assad is uncooperative.

'It was extremely well played by the Russians, but we didn't want someone else to go to the U.N. with a resolution that was weak. This is on our terms and the principles are established. It puts Russia in a situation where they can't take a step back after putting a step forward,' said a French diplomatic source.

A White House official says President Barack Obama has agreed to discussions at the United Nations Security Council to Russia's proposal to secure Syria's chemical weapons stockpiles.

The official says Obama discussed the proposal yesterday with French President Francois Hollande and British Prime Minister David Cameron.

Obama has said the proposal marks a potential breakthrough that could halt plans for a U.S. military strike, though he said the details remain unclear.

The official requested anonymity because the officials was not authorised to discuss the private conversations by name.

But rebel forces say the Russian proposal 'is a cheap trick to buy time for the regime to kill more and more people,' said Sami, a member of the local opposition coordinating committee in the Damascus suburb of Erbin, also hit by last month's chemical attack.

However, any deal with Syria to hand over its chemical weapons in the middle of a chaotic civil war would be difficult for inspectors to enforce and destroying them would likely take years, U.S. officials and experts caution.

Syria's strongest backer, Russia, proposed on Monday that Damascus save itself from a U.S. military strike over its alleged use of chemical weapons by putting its stockpiles under international control.

The proposal was welcomed by Syria and seized upon by the secretary-general of the United Nations. U.S. President Barack Obama said the offer was a potential breakthrough but had to be handled with skepticism.

Syria has never signed a global treaty banning the storage of chemical weapons and is believed to have large stocks of sarin, mustard gas and VX nerve agents.

The actual use of chemical weapons is banned by a 1925 treaty to which Damascus is a signatory.

Accounting for Syria's chemical arms cache - believed to be spread over dozens of locations - would be difficult, as would be shielding arms inspectors from violence.

'This is a nice idea but tough to achieve,' said one U.S. official speaking on condition of anonymity.

'You're in the middle of a brutal civil war where the Syrian regime is massacring its own people. Does anyone think they're going to suddenly stop the killing to allow inspectors to secure and destroy all the chemical weapons?' the official said.

However, Russia says it is working on an 'effective, clear, concrete' plan for putting Syria's chemical weapons under international control and is discussing the details with Damascus, Foreign Minister Sergei Lavrov said on Tuesday.

Lavrov told reporters the plan would be presented to other nations soon and that the proposal, which Moscow hopes will avert possible U.S. military strikes on Syria, was not entirely Russian and grew out of contacts with the United States.

It also emerged today that Syrian rebels may launch a chemical weapon at Israel to provoke an international reaction.

Russian Foreign Minister Sergey Lavrov, left, and his Syrian counterpart Walid al-Mouallem . They say they will push for the United Nations to continue their probe into the use of chemical weapons

Multiple sources have made the claim, according to Russia Today, an English language news network based in Russia. The rebels intend the attack to be a 'major provocation', according to the network

A western journalist released after being held hostage in Syria for five months has claimed President Assad’s regime was not responsible for the use of chemical weapons in a Damascus suburb.

Belgian writer Pierre Piccinin, who was freed on Monday, said that the rebel captors who held him prisoner claimed that it was insurgents rather than President Bashar al-Assad who had ordered the Ghouta massacre.

Piccinin said that he and Domenico Quirico, an Italian journalist who was held and released with him, heard their jailers talking about the chemical weapon attack and saying that Assad was not to blame.

His co-captive Quirico confirmed that he too had overheard the conversation through a closed door but said that he had no evidence to corroborate what he heard.

Piccinin said the hostages despaired when they learnt that the U.S. was planning to launch retaliatory air strikes against the Assad regime over the Damascus attack.

A Syrian man mourning over a dead body after an alleged poisonous gas attack fired by regime forces, according to activists, in Douma town, Damascus, Syria

He told Belgian RTL radio: ‘It wasn't the government of Bashar al-Assad that used sarin gas or any other gas in Ghouta.’

‘We are sure about this because we overheard a conversation between rebels. It pains me to say it because I've been a fierce supporter of the Free Syrian Army in its rightful fight for democracy since 2012.’

‘We were prisoners, stuck with this information and unable to report it,’ he said.

Piccinin and Quirico were taken hostage in early April four days after arriving in Syria. They eventually ended up in the hands of the Islamist rebel group the Farouq Brigades.

Meanwhile, a U.S. defence chief says Military action against Syria will deter North Korea from using chemical weapons.

Slaughter: More than 110,000 people have died in the Syrian civil war so far

Under secretary of defence for policy James Miller said a retaliatory strike against the Syrian government would uphold the international norm that chemical weapons must not be used.

Defence secretary Chuck Hagel has warned that North Korea possesses a massive stockpile of chemical weapons that threatens South Korea and the 28,000 US troops stationed there.

Andrew Sullivan at Kim Eng Securities in Hong Kong said markets were boosted by the easing of concerns over Syria in the short term and continuing good data out of Japan and China, Asia's two biggest economies.